Field of Invention
The present invention relates to an image printing device and a method therefor, and more particularly to a movable pressing and light-shielding mechanism for digital stereo image printing and a method therefor.
Description of Related Arts
With the gradual development of digital stereo image industry, the digital stereo image printing device has developed from small sized digital stereo images printing devices adopting LCD (Liquid Crystal Display) as a display device for projection imaging to digital laser stereo printing devices adopting laser scanning exposure imaging.
Due to the consumers have different vision distance on digital stereo images and different appreciating and accepting requirements for visual environments, stereo grating photographic materials adopted by digital stereo printing device are different. The digital stereo printing device generally utilizes two types of stereo grating photographic materials. The commonly utilized stereo grating photographic material is an ultra-thin shaped stereo grating photographic material which curls easily, has a thin thickness, fine optical grating lines and is directly coated with silver halides on the back of the optical grating or adheres the photosensitive material and the optical grating to form an ultra-thin shaped stereo grating photographic material. The ultra-thin shaped stereo grating photographic material is simple and convenient for printing technique of a digital stereo printing device. In addition the ultra-thin shaped stereo grating photographic material is firstly combined, then performed with projection sensitization, and then are printed and dried to form a stereo. This kind of stereo images has a fine quality and a close viewing distance.
Another kind of stereo grating photographic material has a high thickness and is not capable of crimping, the optical grating has thick lines. Thus this kind of stereo grating photographic material can't be put into a stereo printing system for an automatic printing, can't be covered with silver halides on a back of the optical grating. Furthermore, the photosensitive material and the optical grating can't be adhered in advance. This kind of thick optical grating photographic material has a complicated printing technique in the digital stereo printing device. This kind of thick optical grating photographic material can only be performed with superimposition firstly and then projection to have an exposure of a latent image. Then the photographic material and the optical grating are separated, printed and dried to form an image, and then the image is combined with the optical grating to from a stereo. This kind of stereo has a far vision distance, a good stereo sense. However, the method is not suitable for printing devices of common digital stereo images. In addition, besides the digital stereo printing device, the method requires a high quality of technical skills, has complicated techniques and unsteady quality. The stereo partial focus point is fuzzy sometimes, which is particularly critical to the success of composition of the image and the optical grating by lines.